Completion assemblies are used in a variety of well treatment operations. Generally, a completion assembly is positioned in a wellbore and a service tool is used in cooperation with the completion assembly to perform the well treatment. In some applications, the well treatment comprises a sand control operation in which a gravel pack is created in the annulus around the completion assembly. The gravel pack helps filter out sand and other particulates from a desired production fluid entering the wellbore.
In some well treatment applications, multiple well zones are treated along a wellbore. The treatment of multiple zones can be accomplished with multiple trips downhole, however this can be expensive and time-consuming. Multi-zone treatments have been attempted by making a single trip downhole with the completion assembly and service tool. However, difficulties arise in isolating zones to be treated. In a sand control application, for example, return fluids and reverse out fluids must be conveyed uphole from the formation being treated and past untreated zones. Relatively complex and/or limited flow paths have been constructed in an attempt to remove such fluids while isolating the untreated well zones.